This invention relates generally to the automatic handling of electronic components and is particularly directed to the automatic orienting and positioning of electronic components for engagement by a robotic gripper.
The high speed assembly of circuit boards makes use of automatic component insertion equipment for the positioning of electronic components upon the circuit board, or substrate. The component is typically positioned upon a first side of a circuit board with its conductive leads inserted through predrilled apertures in the board. The component leads are then crimped on a second side of the circuit board for electrical coupling with linear conductors typically in the form of metal foil. In this type of automatic circuit board assembly arrangement, a conveyor typically displaces the board to sequentially arranged work stations whereat various components are mounted on the circuit board by means of a numerically controlled component insertion apparatus. Because the economics of circuit board asembly requires high speed operation and the aforementioned component insertion apparatus typically possesses limited positioning and oomponent grasping flexibility, a highly accurate component delivery arrangement is necessary for proper positioning and orientation of the electronic component prior to engagement by the automatic insertion apparatus.
In the automatic feeding of electronic components, the fewer times the component is re-oriented during the feeding process the less the likelihood of misplacement or misalignment of the component handling apparatus and the less likely is the component handling apparatus to be obstructed and an interruption in component delivery to occur. Ideally, each component is fed in sequence to a precisely defined location in a predetermined orientation without any re-positioning or re-orienting of the component necessary from when it exits the component feed apparatus to its engagement and removal by the component gripper apparatus. One example of a 90.degree. re-orientation of the electronic component following its exit from a delivery tube can be found in U.S. patent application Ser. No. 650,934, filed Sept. 14, 1984 in the names of Carl Campisi and Richard Schmid and assigned to the assignee of the present application. The high, speed, 90.degree. rotational displacement of each of the deposited components prior to engagement by a gripper mechanism increases the likelihood of component displacement from the positioning apparatus and either the failure to insert a component in circuit or a jamming of the component delivery system.
Prior art component delivery mechanisms frequently utilize a gravity feed arrangement wherein each electronic component is deposited by gravity upon a carriage assembly. This downward displacement by gravity of the electronic components through an opening in a lower portion of a delivery tube frequently causes a re-orientation of the electronic component resulting in its misalignment with the component receiver or jamming of the component delivery mechanism such that linear displacement of the component delivery mechanism may be inhibited or even prevented. Moreover, elaborate precautions must typically be implemented in order to prevent the deposit from the feeder tube of only a single component at a time as the simultaneous deposit of more than one component will necessarily jam a delivery mechanism having precisely defined dimensional tolerances necessitated by the continuous, rapid movement of the component displacement assembly. Jamming of the delivery mechaniam causes an interruption in the automatic feeding process and may even damage the mechanism.
The component handling apparatus of the present invention addresses these and other problems encountered in the prior art by handling the electronic components in a manner which does not require component re-orientation in positioning it for grasping and displacement by a robotic gripper. The component handling apparatus of the present invention provides component lead straightening, precisely determines component orientation by means of an optical sensor, and displaces the component a minimal distance prior to engagement by the gripper mechanism.